How to remove rust stain from shell

[bwspa]

I have some rust stains forming on the top of the shell above the water line near the diverter.  What is a safe way to remove this?  I do not have high iron water (actually have high hardness city water).

Tub is white so it shows very easily.  Thanks

[Sam]

Vinegar and baking soda

[MarKee]

If the vinegar and baking soda doesn't work, try Goof-Off on a rag

[LakeMomNY]

I stuff Vitamin C tablets in a small sock and then use it like a sponge - if that makes sense - to wash them off.

[The Wizard of Spas]

I stuff Vitamin C tablets in a small sock and then use it like a sponge - if that makes sense - to wash them off.

+1

Iron Oxide is chemically dissolved by Citric Acid (Vitamin C beats Rust ever time)